The very popular and ubiquitous rise of the ‘personal’ computer system as an essential business tool and home appliance, together with the exponential growth of the Internet as a means of providing information flows across a wide variety of connected computing devices, has changed the way people live and work. Information in the form of data files and executable software programs regularly flows across the planetary wide system of interconnected computers and data storage devices.
Popular and ubiquitous computer hardware and software architectures have typically been designed to allow for open interconnection via, for example, the internet, a VPN, a LAN, or a WAN, with information often capable of being freely shared between the interconnected computers. This open interconnection architecture has contributed to the adoption and mainstream usage of these computers and the subsequent interconnection of vast networks of computers. This easy to use system has given rise to the explosive popularity of applications such as email, internet browsing, search engines, interactive gaming, instant messaging, and many, many more.
Although there are definite benefits to this open interconnection architecture, a lack of security against unwanted incursions into the computers main processing and non-volatile memory space has emerged as a significant problem. An aspect of some current computer architectures that has contributed to the security problem is that by default programs are typically allowed to interact with and/or alter other programs and data files, including critical operating system files, such as the windows registry, for example. Current open interconnection architectures have opened the door to a new class of unwanted malicious software generally known a malware. This malware is capable of infiltrating any computer system which is connected to a network of interconnected computer systems. Malware is comprised of, but not limited to, classes of software files known as viruses, worms, Trojan horses, browser hijackers, adware, spyware, pop-up windows, data miners, etc. Such malware attacks are capable of stealing data by sending user keystrokes or information stored on a user's computer back to a host, changing data or destroying data on personal computers and/or servers and/or other computerized devices, especially through the Internet. In the least, these items represent a nuisance that interferes with the smooth operation of the computer system, and in the extreme, can lead to the unauthorized disclosure of confidential information stored on the computer system, significant degradation of computer system performance, or the complete collapse of computer system function.
Malware has recently become much more sophisticated and much more difficult for users to deal with. Once resident on a computer system, many malware programs are designed to protect themselves from deletion. For example, some malware programs comprise a pair of programs running simultaneously, with each program monitoring the other for deletion. If one of the pair of programs is deleted, the other program installs a replacement within milliseconds. In another example, some malware will run as a Windows program with a .dlls extension, which Windows may not allow a user to delete while it is executing. Malware may also reset a user's browser home page, change browser settings, or hijack search requests and direct such requests to another page or search engine. Further, the malware is often designed to defeat the user's attempts to reset the browser settings to their original values. In another example, some malware programs secretly record user input commands (such as keystrokes), then send the information back to a host computer. This type of malware is capable of stealing important user information, such as passwords, credit account numbers, etc.
Many existing computers rely on a special set of instructions which define an operating system (O/S) in order to provide an interface for computer programs and computer components such as the computer's memory and central processing unit (CPU). Many current operating systems have a multi-tasking capability which allows multiple computer programs to run simultaneously, with each program not having to wait for termination of another in order to execute instructions. Multi-tasking O/S's allow programs to execute simultaneously by allowing programs to share resources with other programs. For example, an operating system running multiple programs executing at the same time allows the programs to share the computer's CPU time. Programs which run on the same system, even if not simultaneously with other programs, share space on the same nonvolatile memory storage medium. Programs which are executing simultaneously are presently able to place binaries and data in the same physical memory at the same time, limited to a certain degree by the O/S restrictions and policy, to the extent that these are properly implemented. Memory segments are shared by programs being serviced by the O/S, in the same manner. O/S resources, such as threads, process tables and memory segments, are shared by programs executing simultaneously as well.
While allowing programs to share resources has many benefits, there are resulting security related ramifications, particularly regarding malware programs. Security problems include allowing the malware program: to capitalize CPU time, leaving other programs with little or no CPU time; to read, forge, write, delete or otherwise corrupt files created by other programs; to read, forge, write, delete or otherwise corrupt executable files of other programs, including the O/S itself; and to read and write memory locations used by other programs to thus corrupt execution of those programs.
In the case of a computer connected to the Internet, the computer may run an O/S, with several user applications, together comprising a known and trusted set of programs, concurrently with an Internet browser, possibly requiring the execution of downloaded code, such as Java applets, or EXE/COM executables, with the latter programs possibly containing malware. Many security features and products are being built by software manufacturers and by O/S programmers to prevent malware infiltrations from taking place, and to ensure the correct level of isolation between programs. Among these are architectural solutions such as rings-of-protection in which different trust levels are assigned to memory portions and tasks, paging which includes mapping of logical memory into physical portions or pages, allowing different tasks to have different mapping, with the pages having different trust levels, and segmentation which involves mapping logical memory into logical portions or segments, each segment having its own trust level wherein each task may reference a different set of segments. Since the sharing capabilities using traditional operating systems are extensive, so are the security features. However, the more complex the security mechanism is, the more options a malware practitioner has to bypass the security and to hack or corrupt other programs or the O/S itself, sometimes using these very features that allow sharing and communication between programs to do so.
Further, regarding malware programs, for virtually every software security mechanism, a malware practitioner has found a way to subvert, or hack around, the security system, allowing a malware program to cause harm to other programs in the shared environment. This includes every operating system and even the Java language, which was designed to create a standard interface, or sandbox, for Internet downloadable programs or applets.
Major vulnerabilities of existing computer systems lies in the architectures of the computer system and of the operating system itself. A typical multi-tasking O/S environment includes an O/S kernel loaded in the computer random access memory (RAM) at start-up of the computer. The O/S kernel is a minimal set of instructions which loads and off-loads resources and resource vectors into RAM as called upon by individual programs executing on the computer. Sometimes, when two or more executing programs require the same resource, such as printer output, for example, the O/S kernel leaves the resource loaded in RAM until all programs have finished with that resource. Other resources, such as disk read and write, are left in RAM while the operating system is running because such resources are more often used than others. The inherent problem with existing architectures is that resources, such as RAM, or a hard disk, are shared by programs simultaneously, giving a malware program a conduit to access and corrupt other programs, or the O/S itself through the shared resource. Furthermore, as many application programs are of a general nature, many features are enabled by default or by the O/S, thus in many cases bypassing the O/S security mechanism. Such is the case when a device driver or daemon is run by the O/S in kernel mode, which enables it unrestricted access to many if not all the resources.
The most common state-of the-art solutions for preventing malware infiltration are software based, such as blockers, sweepers and firewalls, for example, and hardware based solutions such as router/firewalls. Examples of software designed to counter malware are Norton Systems Works, distributed by the Symantec Corporation, Ad-aware, distributed by the Lavasoft Corporation of Sweeden, Spy Sweeper, distributed by the Webroot Software Corporation, Spyware Guard, distributed by Javacool Software LLC, among others. Currently there are a plethora of freeware, shareware and purchased software programs designed to counter malware by a variety of means. Such anti-malware programs are limited because they can only detect known malware that has already been identified (usually after the malware has already attacked one or more computers).
Network firewalls are typically based on packet filtering, which is limited in principle, since the rules determining which packets to accept and which to reject may contain subjective decisions based on trusting known sites or known applications. However, once security is breached for any reason (for example, due to a software or hardware error, a new piece of malware unrecognized by the anti-malware program or firewall, or an intended deception), a malicious application may take over the computer or server or possibly the entire network and create unlimited damages (directly or indirectly by opening the door to additional malicious applications).
The methods in the prior art are typically comprised of embedded software countermeasures that detect and filter unwanted intrusions in real time, or scan the computer system either at the direction of a user or as a scheduled event. Two problems arise from these methods. In the first instance, a comprehensive scan, detect, and elimination of malware from desired incoming data streams could significantly slow or preclude the interactive nature of many applications such a gaming, messaging, and browsing. In the second instance, newly implemented software screens may be quickly circumvented by malware practitioners who are determined to pass their files through the screen. Newly discovered malware leads to the development of additional screens, which lead to more malware, etc., thus creating an escalating cycle of measure, countermeasure. The basic flaw is that all incoming executable data files must be resident on the computers main processor to perform their desired function. Once resident on that processor, access may be gained to non-volatile memory and other basic computer system elements. Malware exploits this key architectural flaw to infiltrate and compromise computer systems.
The majority of these applications rely upon a scanning engine which searches suspect files for the presence of predetermined malware signatures. These signatures are held in a database which must be constantly updated to reflect the most recently identified malware. Typically, users regularly download replacement databases, either over the Internet, from a received e-mail, or from a CDROM or floppy disc. Users are also expected to update their software engines every so often in order to take advantage of new virus detection techniques (e.g. which may be required when a new strain of malware is detected).
Many of the aforementioned applications are also not effective against security holes, for example, in browsers or e-mail programs, or in the operating system itself. Security holes in critical applications are discovered quite often, and just keeping up with all the patches is cumbersome. Also, without proper generic protection against, for example, Trojan horses, even VPNs (Virtual Private Networks) and other forms of data encryption, including digital signatures, are not totally safe because information can be stolen before or below the encryption layer. Even personal firewalls are typically limited, because once a program is allowed to access the Internet, there are often few limitations on what files may be accessed and transmitted back to a host.
A major problem faced by computer users connected to a network is that the network interface program (a browser, for example) is resident on the same processor as the O/S and other trusted programs, and shares space on a common memory storage medium. Even with security designed into the O/S, malware practitioners have demonstrated great skill in circumventing software security measures to create malware capable of corrupting critical files on the shared memory storage medium. When this happens, users are often faced with a lengthy process of restoring their computer systems to the correct configuration, and often important files are simply lost because no backup exists.
Therefore, what is needed in the art is a means of isolating the network interface program from the main computer system such that the network interface program does not share a common memory storage area with other trusted programs. The network interface program may be advantageously given access to a separate, protected memory area, while being unable to initiate access to the main computer's memory storage area. With the network interface program constrained in this way, malware programs are rendered unable to automatically corrupt critical system and user files located on the main memory storage area. If a malware infection occurs, a user would be able to completely clean the malware infection from the computer using a variety of methods. A user could simply delete all files contained in the protected memory area, and restore them from an image residing on the main memory area, for example.
Other discussions of malware, its effects on computer systems, techniques used by malware practitioners to install malware, and techniques for detection and removal, may be found in the published literature, and in some of the patents and applications previously incorporated by reference. Reference to malware may be found in a technical white paper entitled “Spyware, Adware, and Peer-to-Peer Networks: The Hidden Threat to Corporate Security.”, by Kevin Townsend, © Pest Patrol Inc. 2003. Pest Patrol is a Carlisle; Pa. based developer of software security tools. Another reference is a technical white paper entitled “Beyond Viruses: Why antivirus software is no longer enough.” by David Stang, PhD, © Pest Patrol Inc. 2002. Yet another reference is “The Web: Threat or Menace?” from “Firewalls and Internet Security: Repelling the Wily Hacker”, Second Edition, Addison-Wesley. ISBN 0-201-63466-X, Copyright 2003. The foregoing references are incorporated by reference as if reproduced herein in their entirety.